Field
The present disclosure generally relates to devices for humidifying respiratory gases. More particularly, the present disclosure relates to heating arrangements, sensors, and control systems for use with devices for humidifying respiratory gases.
Description of Related Art
Respiratory disorders deal with the inability of a sufferer to effect a sufficient exchange of gases with the environment, leading to an imbalance of gases in the sufferer. These disorders can arise as a pathological consequence of an obstruction of the airway, insufficiency of the lungs in generating negative pressure, an irregularity in the nervous function of the brain stem, or some other disorder. Treatment of such disorders is diverse and depends on the particular respiratory disorder being targeted. In the first instance, a constriction of the airway, otherwise known as an obstructive apnea or a hypopnea (collectively referred to as obstructive sleep apnea or OSA), can occur when the muscles that normally keep the airway open in a patient relax during slumber to the extent that the airway is constrained or completely closed off, a phenomenon often manifesting itself in the form of snoring. When this occurs for a significant period of time, the patient's brain typically recognizes the threat of hypoxia and partially wakes the patient in order to open the airway so that normal breathing may resume. The patient may be unaware of these occurrences, which may occur as many as several hundred times per session of sleep. This partial awakening may significantly reduce the quality of the patient's sleep, over time potentially leading to a variety of symptoms, including chronic fatigue, elevated heart rate, elevated blood pressure, weight gain, headaches, irritability, depression, and anxiety.
In general, respiratory disorders are commonly treated by the application of gases at a pressure or flow greater than normally experienced by the patient under ambient conditions. In order to ameliorate discomfort and/or mucosal tissue damage that may rise from administration of cold and/or dry gases, the gas used to treat the respiratory disorder may be humidified. In some configurations, the gas may be humidified by forcing the gas to travel through a passover-type humidification chamber containing water and a heater for heating said water. In such a configuration, the heater encourages the evaporation of the water, which in turn imbues the stream of air with moisture.